Anti-detonation fuel delivery system

ABSTRACT

A fuel processing device is provided that produces properly sized fuel aerosol particles that when mixed with combustion air, reduces or eliminates detonation (knock) in internal combustion engines thus reducing fuel octane requirements for engines of a given compression ratio. The device includes an adapter between a fuel injector and a port for the fuel injector, the adapter being generally of a hollow cylindrical configuration. A plurality of plates are disposed in the adapter, the plates provided with a central opening, with radially extending slots extending away from the central opening. Each slot has one edge configured with a vane that creates turbulence in the air/fuel mix passing through the adapter so that larger droplets are broken up into smaller droplets until an optimum droplet size is reached.

FIELD OF THE INVENTION

This invention relates to internal combustion fuel systems, andparticularly to such a system wherein an atomizing device communicatingwith an interior of an intake manifold or throttle body serves toaerosolize the fuel so that droplet size of the fuel is withinpredefined limits, allowing the engine to operate with a highercompression ratio and/or a lower octane rating.

BACKGROUND OF THE INVENTION

A large number of methods for producing fuel-air mixtures forreciprocating internal combustion engines are known, and many arepatented. As far as Applicant is aware, previously disclosed methods allattempt to produce a fuel vapor mixed thoroughly with air. In many ofthese methods, fuel is heated, some instances to approximately a boilingpoint of the fuel, in order to convert the fuel to a gas prior to itsinduction into a combustion chamber. Virtually all attempt to minimizefuel droplet size based on the belief that fuel droplets in the fuel/airmixture cause inefficient combustion and generate more pollutants in theexhaust.

However, providing a stoichiometric fuel/air mixture wherein the fuel isin a vapor form also provides a readily explosive mixture. This becomesa problem when loading on an engine causes pressure increases incombustion chambers thereof sufficient to raise a temperature of thefuel/air mixture to or beyond its ignition point. This in turn causesthe fuel/air mixture to explode all at once (rather than burning evenlyin an outward direction from the spark plug), a condition commonly knownas “knock” due to the knocking noise created as bearings of the rotatingparts of the engine are slammed together under the force of theexplosion. As might be imagined, such a condition is deleterious tobearings and other parts of the engine, and greatly shortens enginelife.

In accordance with the present invention (referred to in one embodimenthereinafter as “Star Tube”), an apparatus and process of fluid fueltreatment is provided, the process converting fuel into an aerosolhaving droplets of a predetermined maximum size with a minimum of vaporbeing generated in the induction air stream. The object of thisinvention is to allow internal combustion engines such as Otto-cycleengines, two-stroke engines, Wankel-type engines and other such enginesthat compress a fuel/air mixture just prior to sparked ignition tooperate on a fuel-air mixture that is stoichiometrically correct withoutdetonation, thus reducing fuel octane requirements for engines of agiven compression ratio. This is achieved because fuel droplets “burn”at a slower rate than a gas/air mixture which explodes, thus reducingthe tendency of an engine to knock. Here, it is believed that a fueldroplet within the aforementioned range burns in layers, so that as anouter layer of the fuel droplet is burned off, oxygen is temporarilydepleted around the droplet. Oxygen then surrounds the droplet ascombustion gases around the droplet expand and dissipate, allowing thenext layer to burn off. This process is repeated until the fuel dropletis fully burned. Of course, where too much fuel vapor is present, knockmore readily occurs.

In accordance with the foregoing, it is one object of the invention toprovide apparatus for decreasing or eliminating engine knock byaerosolizing fuel into droplets of a predetermined size. It is anotherobject of the invention to provide apparatus for generating a fuel/airmixture wherein the fuel is incorporated into the droplets to as greatan extent as possible, with as little vapor as possible. It is yetanother object of the invention to enable an internal combustion, sparkignition engine to operate normally without knock using a fuel of alower octane rating than the engine is rated for. Other objects of theinvention will become apparent upon a reading of the following appendedspecification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of the broadest concept of the inventionwherein a variety of devices may be used as one component of the system.

FIG. 1a is a diagrammatic view of a particular anti-detonation fueldelivery system of the present invention.

FIG. 1b is a diagrammatic view showing particulars of constructionrelated to another embodiment of the present invention.

FIG. 2 is a cut-away view of the embodiment shown in FIG. 1a.

FIG. 2a is an end view of the embodiment shown in FIG. 1a.

FIG. 2b is a cut-away view showing particulars of construction ofanother embodiment of the invention.

FIG. 3 is a top view of a star spin-and-shear plate of the embodiment ofFIG. 1a.

FIG. 4 is a side view of the Star Spin-and-Shear-Plate of the embodimentof FIG. 1a.

FIG. 5 is a cut-away view of a star spin-and-shear plate illustratingparticulars of operation.

DETAILED DESCRIPTION OF THE DRAWINGS

The basic principle of operation of the present invention involvesproviding a fuel spray, having droplets of a predetermined size,generally from about 50 microns or so down to just larger thansub-micron clumps of fuel generally considered to be vapor. In abroadest concept of the invention, and as shown in FIG. 1, a throttlebody or intake manifold 1 is provided with any device 2 capable ofreceiving liquid fuel from a fuel tank 3 and associated fuel pump 4 andconverting it into droplets 5 of the described size and providing thedroplets to an induction airflow of an internal combustion engine.Droplets that are too large, and to any extent possible fuel vapor, arereturned to tank 3 via line 6.

Oversize droplets can be isolated by centrifugal force in a vortex orcontrolled path, or screens can be used to trap oversized particles.

Pursuant thereto, devices such as piezoelectric atomizers, ceramicsieves receiving pressurized fuel, specialized nozzles such as SIMPLEX™nozzles and LASKIN™ nozzles, air pressure atomizers, rotary cupatomizers, inkjet-like devices that operate using inkjet or bubble jettechnologies, insecticide spray nozzles and other nozzles such asSPRAYTRON™-type nozzles available from CHARGED INJECTION CORPORATION ofNew Jersey may be incorporated into a throttle body or intake manifold.In addition, devices such as the NEBUROTOR™ available from IGEBAGERAETEBAU CORPORATION of Germany. This device uses a motor-drivenrotating blade to break the liquid fuel into droplets of the desiredsize.

In one particular embodiment of the invention, part of the normalairflow through the intake manifold is diverted and utilized to processfuel sprayed by one or more fuel injectors into droplets of apredetermined size. This embodiment uses a series of vanes angularlypositioned to spin the diverted induction air flow and fuel droplets,forcing the air and fuel droplets in a flow path through slits that areformed by the vanes. The vanes also create turbulence in the flow path,causing mechanical breakup of the fuel into smaller droplets. Withinthese combined actions, the spiral path creates centrifugal force on thefuel droplets that tend to tear the droplets apart, and the turbulencehelps to shear apart oversized particles. As the droplets becomesuccessively smaller as they pass through the star tube, it is believedthat the centrifugal and shearing forces overcome surface tension in theliquid fuel droplets until an equilibrium point between the centrifugaland shearing forces and the surface tension of the droplet is reached.Also, as the particle sizes approach the desired upper limits, spinalong the axis of the star tube causes particles that are still abovethe desired size to drift outward from centrifugal force into narrowerregions of successive vanes for more processing, while allowingcorrectly sized particles to flow generally near or through centralopenings along the axis of the star tube. After exiting the star tube,the resulting aerosol is mixed with the rest of the induction air streamand the fuel-air mixture is drawn into a combustion chamber.

The method described herein creates a fuel-air mixture that allows afuel with a, lower octane rating to be used without knock in a highercompression spark ignition engine than would otherwise be the case. Asstated, many combinations and permutations of various devices andmethods for producing aerosols with approximately the same droplet sizemay be utilized. Through extensive experimentation, Applicant hasdiscovered that when an aerosolized fuel with properly sized droplets isused in an internal combustion spark ignited engine, the aerosolizedfuel has less of a tendency to cause the engine to knock. In the instantinvention, it is believed the extent to which knocking of an engine isreduced is dependant on how well fuel particle size is controlled. Fuelparticles that are too large will not burn completely, causing loss ofpower and unburned hydrocarbons in the exhaust gas. On the other hand,if the droplets are too small and too much vapor is developed in theaerosolization process, the smaller droplets and vapor may spontaneouslydetonate (knock) due to increased engine compression as the engine isloaded or if the compression ratio of the engine is too high for theoctane rating of the fuel. Empirically derived results have demonstratedthat a generally desired particle size range is less than 50 microns orso in diameter and larger than the sub-micron clumps of molecules thatare generally considered to be vapor. Within this range, a droplet sizeof about 20 microns or so appears to be optimal. Above a droplet size ofabout 50 microns, power begins to drop off and unburned hydrocarbonlevels began to increase in the exhaust gases. In an engine whereexhaust gases are closely monitored by an engine controller, theseunburned hydrocarbons could cause the engine controller to reduce fuelin the fuel-air mixture, creating a situation where the engine is notproducing rated power.

As described herein, FIG. 1a illustrates, by way of example, onepossible embodiment of a star tube adapter 10 which may be mountedbetween a conventional fuel injector 12 and an injection port 14 in athrottle body 16 (dashed lines) or in an intake manifold of an internalcombustion engine. Conventionally, a fuel injector 10 is fitted toinjection port 14 so as to provide a spray of fuel to induction air, asindicated by arrow 18, flowing through the throttle body and intakemanifold. As shown, one end B of star tube adapter 10 is configured toreceive the injection end of a fuel injector 12, with the other end A ofthe fuel injector configured so as to be mountable in a fuel injectionport 14 that otherwise would receive the fuel injector. In somecurrently manufactured engines, there is more than 1 fuel injector inrespective ports in the throttle body that provide fuel to all thecylinders of the engine, thus there is a star tube for each respectiveinjector. A portion of the induction air 18 flowing through the throttlebody (or intake manifold) 16 enters openings O in end B of the startubes to create turbulence in order to break up the fuel droplets. Inother engines where there is a fuel injector and corresponding injectionport for each combustion chamber, these ports are typically located inthe intake manifold proximate to a respective intake port or valve, withthe fuel injector body mounted outside the intake manifold. Here, and asstated, the star tube may be configured at this end A to fit theinjection port, as by being of a reduced diameter, and be configured atthe other end B as an injection port so as to receive the injecting endof a fuel injector. In this instance, a portion of the induction air maybe routed or directed to the star tube so as to create a motive airflowtherethrough, or a carrier gas may be provided independently of theinduction airflow. This carrier gas may be an inert gas such as drynitrogen or filtered atmosphere gasses, or a combustible gas such aspropane or butane. Where propane or butane is used, an octane rating offuels having a lower octane rating is beneficially increased due to thehigher octane rating of propane and butane. In addition, the carrier gasmay be or include an oxidizing gas such as nitrous oxide, which may besupplied through the star tubes in a quantity or proportion commensuratewith its use as a racing additive. In this instance, the motive flow ofgas through the star tube may be switched between another gas that mayor may not be combustible and the nitrous oxide. In addition, othergasses that raise octane rating of the fuel, provide anti-pollutionqualities, increase power output of the engine or increase surfacetension of the fuel droplets may also be used, either alone or incombination. Further, vapors from liquids may also be used, such asalcohol. Thus, it should be apparent that any gas or vapor orcombination thereof may be used for generating a gaseous flow throughthe star tubes, this flow being of a sufficiently high rate so as togenerate turbulence to mechanically break the fuel droplets into smallerdroplets having a size within the predetermined range as describedabove.

As shown in FIG. 1b, a supply of gas may be coupled to the star tubes byan annular hollow collar 20 open on a bottom side next to openings O inthe end of the star tubes, and fitted to a top of the star tubes.Injectors 12 fit in the opening of the annular collar and communicatewith an interior of the star tube assembly. The supply of gas 22 isprovided to collar 20, and may be valved by a valve 24 (dashed lines)operable to release a burst of gas in conjunction with the fuelinjector, being energized to release a spray of fuel. In otherinstances, the gas would simply flow continuously. In anotherembodiment, star tubes 10 may simply be closed at a top and except for aport for the fuel injector, with gas 22 being supplied directly to thestar tubes. In all instances where needed, the star tube and fuelinjector are conventionally mounted and supported by brackets or similarstructure (dashed lines in FIG. 1a), as should be apparent to oneskilled in the art.

As many modern engines test exhaust gas products to determine quantityof fuel to be provided to the induction air, addition of any of theaforementioned gasses or vapors to induction air would be compensatedfor by the engine controller in order to keep the fuel/air mixture at astoichiometric proportion. Further, in the instance where there is afuel injector for each combustion chamber, an aftermarket or OEMmanifold may be provided with provisions to house the fuel injectors andstar tubes in a position proximate a respective intake port of acombustion chamber, with possibly an air scoop or independent channelcast or mounted in the interior of the intake manifold to direct anappropriate proportion of induction air through the star tubes.Alternately, an amount of gas or vapor flowing through the star tubesmay be controlled, as, by a computer such as an engine controller, tomaintain or assist in maintaining a stoichiometric fuel/air mixture orto increase or decrease a flow of motive gas through the star tube tocompensate for changes in induction airflow, as when the acceleratorpedal is depressed to a greater or lesser degree. Alternately,mechanical linkages coupled to valving apparatus may be employed forsuch increases and decreases in the motive flow through the star tubes.

With reference again to FIG. 1a, and as described, a Star Tube 10 may bemounted in the throttle body or intake manifold 16 between a respectivefuel injector and an associated injection port. Typically, the liquidfuel, is pumped by a low pressure fuel pump 26 in a fuel tank to a highpressure fuel pump 28, which conventionally develops fuel flow as shownto the fuel injectors 12. Injectors 12 produce pulsed sprays of aerosolfuel as controlled by an engine controller (not shown), which determinesboth quantity and timing of the sprays. These sprays of aerosol fuelfrom the fuel injectors 12 are fed directly into Star Tubes 10 where thespray is processed into smaller droplets of 50 microns or less indiameter, and subsequently fed into the throttle body, intake manifoldor any other regions in which fuel would be appropriately injected.Induction air and the fuel aerosol as processed by the Star Tubes isthen drawn into a combustion chamber (not shown). The fuel feeding thefuel injectors may be conventionally regulated to a constant pressure byfuel pressure regulator 30, which relieves excess pressure by bleedinghigh pressure fuel via return line 32 to fuel tank 34 as shown by arrow36, along with any vapor that has formed within the high pressure feedline. Of course, any of the devices shown and described for FIG. 1 maybe substituted for the star tubes 10.

FIG. 2 shows a cross section of one of Star Tubes 10. Initially, at anend B of the Star Tube that receives an injection end 38 of a fuelinjector, a cap, as shown enlarged in FIG. 2a, or other closure 40 maybe configured with an opening 41 which may be tapered to match a taperof fuel injection end 38. Positioned in cap 40 around injection end 38is a plurality (9 shown) of openings O, which may be sized to handle airflow through the star tube for a particular engine. In the example ofFIG. 2, a star tube constructed for use in a 350 cubic inch displacementengine is shown. In a popular, conventional version of this particularengine, there are four fuel injectors mounted in ports positioneddirectly in the airflow of a throttle body of the engine, with the fuelinjector and star tube mounted and supported by brackets (schematicallyillustrated by dashed lines). As such, a star tube is mounted betweeneach port and a respective fuel injector. While a plurality of openingsO are disclosed, other sizes and types of openings are also workable.For instance, as shown in FIG. 2b, a single, annular opening 37 aroundend 38 of fuel injector 12 may be provided, possibly out to the innerdiameter of the star tube, or a smaller number of larger openings O maybe constructed in end B of the star tubes. In addition, and as stated,valves coupled to openings O or a single valve coupled to the end of thestar tube may be used to release a burst of gas or vapor in conjunctionwith injector 12 being energized to release a spray of fuel. Asdescribed above, a most significant feature of the star tubes and gasflow therethrough is that the fuel droplets are broken up into dropletssmaller than about 50 microns or so. In addition, formation of dropletsby the star tubes tends to minimize fuel vapor formation in theinduction airflow.

As stated, a star tube that has been found to work well for the 350cubic inch engine is shown in FIG. 2. In this embodiment, the tubeportion 42 is about 1.5 inches outside diameter and about 1 inch insidediameter. Cap 40 is provided with a plurality (9 shown) of openings Oaround a periphery of the cap, these openings O each being about 0.187inch in diameter. A central opening 44 in cap 40 is about 0.5 inch indiameter to receive the fuel injector end 38. In the instance wherethere is simply an annular opening around end 38 of the fuel injector incap 40 or where cap 40 is omitted entirely, the injector body would besupported exterior of the star tube so that end 38 is generallycoaxially positioned with respect to the end of the star tube, formingan annular opening around the injector end 38.

The region of the tube portion 42 immediately adjacent cap 40, which maybe about 0.250 inches thick, is tapered on an interior side over about a0.5 inch length of the tube portion as shown in order to provide aclearance for openings O, which may be located around a periphery of cap40 and to provide a feeder region for fuel spray from the injector.Additionally, this taper may somewhat compress air flowing throughopenings O, advantageously speeding up velocity of air flowing throughthe star tube. Alternately, the star tube may be constructed of thinnermaterial. As such, the spray of fuel from the fuel injector is initiallyintroduced into the Star Tube along with a flow of, gas. The flow of gasand fuel droplet spray then encounters a plurality (5 shown) of seriallyarranged Star-Spin-and-Shear-Plates 46 spaced about 0.75 inch from oneanother, with the closest star plate to the injector being spaced about0.75 inch from the interior transition of the taper. The starspin-and-shear plates may be mounted in the tube as by an interferencefit between edges of each plate and an interior of a tube, by lips orsupports constructed along an interior surface of the tube that theplates rest on, by bonding the plates within the tube, securing byfasteners, or any other obvious means for securing the plates within thetube, as represented by blocks 48 in FIG. 2. Further, in the event aplate inadvertently loosens within a star tube, an end of the star tubeclosest to a respective intake manifold port or throttle body port maybe slightly narrowed or otherwise constructed so that the starspin-and-shear plate is not drawn into the intake manifold where itcould impact a valve or enter a combustion chamber.

The Star spin-and-shear plates 46 each have a plurality of types ofopenings (FIG. 3), these openings being a central opening 50 of about0.5 inches in diameter and a plurality, in this instance 6, of narrowingspoke-like openings or slits 52 communicating with and radiallyextending from central opening 50. As shown in FIG. 3, openings 52 maybe initially relatively wide at central opening 50, and angularlyconverge to a point 54 radially positioned at approximately 50 percentto 85 percent or so of a diameter of the plates 46. A ratio of thediameter of plate 46 with respect to central opening 50 may be about 3to 1, but a range of about 1.5 to 1 or so up to about 5 to 1 has beendiscovered to be workable.

As a feature of the invention, FIGS. 3-5 also illustrate a downwardlydepending vane 56 positioned on edges of each of openings 52. Vanes 56may be downwardly angled, as shown in FIGS. 4 and 5, at about from a fewdegrees to almost 90 degrees from a plane of the plate. However, in onecontemplated embodiment that works well, a vane angle of about 40degrees is used. Vanes 56, in conjunction with an opposed edge 58 ofopenings 52, serve to provide edges 60 (FIG. 5) that create turbulencewhen the airflow passes through a respective opening 52. This turbulenceshears and breaks up larger fuel droplets into smaller droplets as theflow passes through successive star plates 46 until a desired dropletsize of about 50 microns is reached. In addition, since all vanes 56 maybe oriented to direct airflow in the same direction, a net spin of theaerosol mix through the star tube may be provided (clockwise in FIG. 3),causing larger fuel droplets to drift outward due to centrifugal forcetoward a perimeter of the Star Tube, where they are forced to passthrough a narrower portion of openings 52 where turbulence through thenarrower opening is greater. Here, this greater turbulence developed bythe narrower regions of openings 52, in combination with sharp or abruptedges 60, causes the larger droplets to be broken up into smallerdroplets. As such, smaller fuel droplets that are not as greatlyaffected by centrifugal force are prone to pass through portions ofopenings 52 closer to, or through central openings 50.

In addition, it has been found that the vanes may be angled eitherupward or downward, with approximately equal performance with respect tobreaking up larger droplets into smaller droplets. Here, while therotation imparted by downwardly extending vanes causes axial spin offuel/air mixture through the star tube, upwardly extending vanes alsocreates spin through the star tube, in addition to the aforementionedshearing action around edges of openings 52.

While a star shear-and-spin plate is disclosed, other configurations ofplates with openings therein have been tested and have been found towork, albeit to a lesser extent but to an extent which may be practical.For instance, in one test the star shear-and-spin plates were replacedwith conventional flat washers. In this example, spin of the airflow waseliminated while providing relatively sharp or abrupt edges aroundcentral openings in the washers that developed turbulence. Thisembodiment worked about 40% as well as the star shear-and-spin plateshaving radially extending slits. From this, it should be apparent thatopenings of any configuration in the plates may be used. This wouldinclude star-shaped openings, rectangular openings, square openings, orany other opening configuration. In addition these openings may bealternated between successive plates so that a first plate may have oneparticularly configured opening and the next plate may have adifferently configured opening, and so forth.

At an opposite end of the Star Tube (the tube configured at thisopposite end to be fitted into a fuel injector port of an intakemanifold or throttle body) the processed fuel/air mixture is drawn intoa throttle body or intake manifold, where the processed fuel aerosolparticles suspended in the carrier air flowing through the star tube aremixed with induction air flowing through the throttle body or intakemanifold and subsequently drawn into a combustion chamber.

While 6 spoke-like openings 52 are shown, more or fewer of theseopenings 52, such as about three or so or more, may be used. Likewise,while 5 star plates are shown, fewer or more of these plates may beused, such as from about 1 to 7 or so. Also, the star tubes, starspin-and-shear. plates and openings in the star plates may be scaled asnecessary depending on displacement of the engine and number of startubes per cylinder.

As a primary function of a fuel injector is to provide a selected amountof fuel as determined by an engine controller, the fuel injector simplyserves as a variable valving device responsive to the engine controller.As such, it may be possible to replace the fuel injector with a valvethat provides the required amount of fuel to a star tube or any deviceas described for FIG. 1 responsive to signal from an engine controller,with the star tube or other device breaking up the fuel into droplets ofthe predetermined size of about 50 microns or so. In addition, the startube may use a series of horizontal vanes to spin the air and fuelmixture through the star tube, forcing the larger fuel droplets to driftoutward and pass through narrower portions of the horizontal slits thatare formed by the vanes, in turn causing their mechanical breakup intosmaller droplets. In this embodiment, the mixture also has induced spinaround the axis of the star tube as well as turbulent spin from passingthrough the slits. The combined spins create centrifugal forces, that incombination with shearing edges, tend to tear the larger droplets apart.

As the droplets get successively smaller, it is believed thatcentrifugal and shearing forces overcome the surface tension in theliquid droplet down to an equilibrium point where the droplets cannot befurther reduced, which as stated is from about 50 microns down tosub-micron clumps just larger than vapor. The resulting aerosol is thenrecombined with the rest of the induction air, with the carrier airpassing through all the star tubes of an engine being up to about 5% orso of the total induction air flow through the throttle body or intakemanifold. The process of breaking up the larger droplets may further beassisted or regulated by additives in the fuel to limit breakup beyond aselected smallest size, such as 1-10 microns or so. Here, the additivemay be selected so as to increase surface tension in the fuel dropletsso that the smallest droplets do not break up into yet smaller dropletsthat may evaporate into vapor. For instance, the addition of a smallamount of heavier oil or a fuel oil to gasoline, or addition of a smallamount of glycerin or castor oil to alcohol, may increase surfacetension or volatility of the fuel so as to facilitate droplet formationand minimize vapor formation.

Several test engines have been adapted with Applicant's invention inorder to test feasibility, practicality and workability of the StarTubes. For instance, one such engine was adapted as described above, andperformed as follows:

Engine:

A Chevrolet 350 CID engine bored out 0.030 to provide about 355 CID anda Compression Ratio of about 10.6:1.

Total runs done: more than 160.

Star Tubes: (Step Diffuser enhanced by Star spin)

Six Star-spoked openings, base to base: ¾ in.

Peak anti-detonation effect in this engine was found with; 5 to 7 Starsteps. With more than 7 steps, power began to drop, probably because offuel restriction. With 3 star plates, the effect was still about 80% ofwhat it was with 5 star plates. In this engine;

Star plate OD: {fraction (15/16)} in.

Tube ID: {fraction (13/16)} in.

Tube OD: 1¼ in.

Smaller sized star plates and tubes still produced an effect but with aproportional reduction in engine power. Sizing of the Star plates maytherefore be a function of airflow (almost akin to engine size) throughthe engine. Considerable latitude appears to exist, but larger area starplates work better with larger displacement engines, and smaller areastar plates work better with smaller displacement engines. As a generalrule, the Star tubes work well when they receive about 5% of the totalinduction airflow through the intake manifold or throttle body. Theopening or openings in cap 12 around the fuel injector tip are generallysized to allow little or no restriction of gas flow through the tube.

Typically, engine runs were from 5000 rpm down to 2500 rpm, with datareadings taken by conventional engine monitoring equipment. Particlesize was measured by a test rig wherein a star tube and associated fuelinjector was set up in a simulated throttle body constructed of atransparent material. An air compressor or fan was used to draw airthrough the simulated throttle body at speeds simulating inductionairflow. Conventional laser interferometry equipment, such as that usedto measure size of pesticide droplets, was used to measure the fueldroplets size just after the star tube. Engine measurements were takenat every 250 rpm from between 1500 rpm up to about 4500 rpm. Criticaldetonation data typically comes in between 3500 and 2800 rpm. Peaktorque typically comes in between 3000 and 4000 rpm. Spark advance wasset for best torque (without detonation, if any). With C-12 (108 octaneracing fuel), there was never any detonation regardless of the amount ofspark advance (this did not exceed 36 degrees). Using a gasoline with anoctane rating of about 80, peak torque with the star tubes was typicallyat about 28 to 30 degrees spark advance. This was always equal to orbetter than peak torque with C-12. The runs with C-12 runs were used toestablish a baseline.

Having thus described my invention and the manner of its use, it shouldbe apparent to those skilled in the art that incidental changes may bemade thereto that fairly fall within the scope of the following appendedclaims, wherein I claim:
 1. A method for providing an air/fuel mixturefor use in an internal combustion engine, said air/fuel mixturepredominantly containing size-limited fuel droplets, the methodcomprising: a) providing a constrained flow path, b) providing at leastone turbulence-inducing device in said constrained flow path whereinsaid turbulence-inducing device comprises a tube containing a pluralityof plates each having at least a centrally located opening therein, witha plurality of slits radially extending from said centrally locatedopening and edges of said slits positioned to direct said flow of saidgas and said droplets in a spiral through said tube, c) introducing aflow of gas into said constrained flow path, d) injecting a liquid fuelinto said constrained flow path along with said flow of gas so that saidliquid fuel is broken up by turbulence into fuel droplets of apredetermined size, e) inserting said flow of gas and fuel droplets of apredetermined size into an induction air flow for intake into combustionchambers of an internal combustion engine.
 2. A method as set forth inclaim 1 wherein said introducing a flow of gas into a constrained flowpath further comprises utilizing a small portion of said induction airflow as said flow of gas.
 3. A method as set forth in claim 1 whereinsaid inserting said flow of gas and fuel droplets into an induction airflow further includes providing said flow of gas and said fuel dropletsof a predetermined size to said induction air flow in a throttle body ofsaid internal combustion engine.
 4. A method as set forth in claim 1wherein said inserting said flow of gas and said fuel droplets of apredetermined size further includes inserting said flow of gas and saidfuel droplets of a predetermined size into an induction air flow in anintake manifold of said internal combustion engine.
 5. A method as setforth in claim 1 wherein said introducing a gas into said constrained aflow path further comprises introducing a combustible gas in saidconstrained flow path.
 6. A method as set forth in claim 1 wherein saidintroducing a gas into said constrained flow path further includesintroducing an oxidizing gas in said constrained flow path.